Method and apparatus for releasing jammed well-drilling tools



Dec. 1943. J. F. KENDRICK 2,336,257

METHOD AND APPARATUS FOR RELEASIN G JAMMED (ELK-DRILLING TOOLS Filed Jan. 9, 1942 6 She ets-Sheet 1 John EKendricK Mum;

Dec. 7, 1943. J. F. KENDRICK 2,336,257.

METHODAND APPARATUS FOR RELEASING JAMMED WELL-DRILLING TOOLS Fi1ed Jan. 9, 1942 GSheets-Sheet 2' ilii METHOD AND APPARATUS FOR RELEASING JAMMED WELL-DRILLING TOOLS Filed Jan 9, 1942 e Sheets-Sheet :5

w. L; mg u 55 5 1943. J. F, KENDRICK 2,336,257

METHOD AND A PPAZRATUS FOR RELEASING JAMMED WELL-DRILLING TOOLS I Filed Jan. 9, 1942 6 Sheets-Sheet 4 Dec. 7, 1943. J. F. KENDRICK 2,

METHOD AND APPARATUS FOR RELEASING JAMMED WELL-DRILLING TOOLS Filed Jan. 9, 1942 6 sheets -sheet 5 JOHN F! KENDRICK 7, 1943. J. F. KENDRICK METHOIj AND APPARATUS FOR RELEASING- JAMMED WELL-DRILLING TOOLS File d Jan. 9, 1942 6 Sheets-Sheet 6 FIG .18.

- JOHN E-IIQENDRICK Patented Dec. 7, 1943 UNIT-Eo- STATES, PATENT orncs ament.

This invention, relates ,to an improved method and apparatus for dislodging., well appliances when the latter become :St'llQkpOlf held against re; leasing movement. V For example, one of theshortcqmings oithe cable tool drill is that the,wel1- mustbekdrilled; to a point below a treacherous formation before any very adequate precaution canbe taken. A ll' this time, there is'gr ave danger-of lthetoolslbe; comin stuck, as a result of cavingsfallingdrom above and wedging the tools against the wallof; the hole. As a safety measure, it is customary, to place a device known as a jarl in the string; of tools, generally directlybelow the socket-to which the cracker or drill ing lineis-attached The usual drill stern is attachedto the jar arid the bit is screwed tether stem.

Such a jar ordinarily tconsists of :a looser link When the tools become stuck, moderation; deavors to adjust therhitch and motion. of the, walking beam or spudde r so that this link opens; and closes with a; snap l on;- each 'strolge of the', temper screw. The efifectiive nessv of" the .jar, del-f pends on the mass above the link, Which'is. gen erally small compared to the mass belowtthelinlc, 25, and to the velocitywof themass above the link? at the instant of imp-act; That thevrnassabove, the link is often inadequate is evldencedby the} fact thatrnany operators place what'is kno as asinlier bar between the jarandthe socket. As 3 the well gets deeper, the elasticity ofthedrilling cable increases and mav n; cliificu lt, 'eve nl' for an experienced" driller, tq adj ustthe motion ofthe beam or spudder to get aproper jarring-action; and to determinewhen there is ;Dresentasatis; factory jarring action. Frequently, it is impos sible to keep ,thejarslfrorh hitting both waysl Occasionally it proves impossible .tof free. thei stuckiools with the drilling jars and someti-rne's} the jars themselves becorne; wedged so they canf,

not be operated. Then it becomesnecessary,to cut or otherwise part the drillinglline and run in with afishing string madeup; With thestern, between the jars and, the socket, with a: suitable fishing tool at the bottom of thejarr There have;

been times when such a fishing-string.has be come stuck also. During all these operations, there is serious danger of the drilling cablebeing whipped off or broken. Allsuch factors-combine, to make all jarring operations hazardous, time 50, consuming, and expensive.

From this brief description, itwill be apparent, that the present art of jarringis ineflective due. the dirficultyof gettingtherdesired jarring,

motion on account 0t theela sticityoi the drill jm ing :line and due. to ,thesrelatively ,greatermass of the devices to be -freed-compared to the-releasing impact that can .be delivered These .con-

ditions are -found not. only in drilling wells with. cable or standard drill, but also when these tools.

arevusedtodeepen or cleanout anold Well;v Also,

when the.tubing ofa producingwell issetin a, packerQthe packer sometimes sticks, resultingin.

a; mer y large mass compared to any releasing impact-that canbe(delivered. The same conditions.

maybe-encountered.whennit is desired to pull casing when a well-is .to be abandoned. Should.

the drill pipe of rotary drilling apparatus become stuck, thereislno effective -wayrto apply jarring actionlto, releaseflit. OtheneXamples could be cited, but these. will servetogive a general under:

standing of the. .prbblerhsinvolved.

It is an objectof this inventionto provide a system utilizing the elastic, properties of the elerr 'ent-fwhich corinectshthestuckhdevice with the. surface of the ground, be itdrilling cable, tubing,

drill pipe, or, casing, to transmit a longitudinal Qr,..CQmpleSSiVe impulse fromflthe surface. to the A stuck. device.-, If Jars are attached to the stuck device, and are ,operative, such an impulse will serve to operate the jar in an effective manner. However,. if no jars .are present, 0r if they are inoperative, such an impulse will subject the, stuck device to an" impact closely analogous to .that .delivered by the usual jar when operatedproperly. Thenthe effect will be like striking. the stuck element. with a, ma ssi ve hammer, the blow, being generated, at the surface. Such impaots will be] effected without running any other device into thewell, whichinturn might become stuck, and these impacts, are] readily controllable as to frequencyand magnitudel It'will be easy to start operationswith a slow successionof gentle impacts, increasing the "intensity: until the stuck can be operated effectively. bythe same sortv of longitudinal impulse generated at the. surface. With this new jarring technique, the frequency,

magnitude, and direction, oftheimp'act are all,

under the positive control of thesoperator.

Thelongitudinal-oncompressiveimpulse is, generated at thesurface. by first-taking an initial tension in the drilling cable, tubing, drill pipe,

asing, r what er t e. elasti lement mayb Then the usual fishing tools can be run, and when jarring action-is required, they.

This downward movement is checked suddenly by impact with a-recoil device before the initial tension in the elastic element has been exhausted. This impact generates the impulse which travels the length of the elastic element to exert a jerk on the stuck device. The"initial tensiom'the magnitude of the secondary tensionimposed by the further stretching of the elastic element, and

the cushion of the recoil device]arefactorswhichI can be controlled or varied, thus making the;

impact of the jar positive in action.

For a further understanding of the invent ion} reference is to be had to the following descrip tion and the accompanying drawings, showing its application to the cable tool drill, wherein: Y

Fig. 1 is, a diagrammatic view illustrating a well-drilling rig provided with the surface located jarring apparatus vention;

Fig.2 is a vertical sectional iew taken through: the hammer and anvil members of the jarring apparatus; r

Fig. 3 is a detail horizontal sectional view taken through the sectionalizedv crib supported base for the anvil member of the jarring apparatus on the plane indicated by the line IIIIII of Fig. 2;

Fig. 4 is a horizontalsectional view on the line IVIV of Fig. 2, developing'the cable clamping construction of the hammer member;

Fig. 5, is avertical'sectional view through the anvil member;

Fig. 6 is a horizontal sectional view taken through said anvil member on the plane indicated by the line VIVI of Fig. 2;

comprising the present ;in'-

Fig. '7 is a vertical sectional view onthe line VIIVII of Fig. 1 and disclosing the crank construction for actuating the drill cable to impart movementto the hammer member of the apparatus;

Fig. 8 isahorizontal sectional view on the plane indicated by the line VIII-- VIII of Fig. '7; Fig. 9 is a vertical sectional view on the line IXIX ofFig.7; v

Fig. 10 is a diagrammatic side elevational view, partly in verticalsection, of a modified form of jar apparatus formed in accordance with the present invention;

Fig. 11 is a vertical sectional view on an en.- larged scale of the jarapparatus illustrated in Fi '10; V v

; Fig. 12 is adetail horizontal sectional viewon the line XII-XII of Fig. 11;

Fig. 13 is a detail vertical-sectional view onthe,

plane indicated by the li ne XIII-XIII of Fig. 11;

Fig. 14 is a horizontal sectional view on the.

plane indicated by the line XIV-X[V of Fig. 11; Fig. 15 is a fragmentary end elevational view of the cable yoke; I Fig. 16 is a detail perspective the yoke-carried hammer-clamping members;

. Fig. 17 is a diagrammatic elevational view,

showing fluid-actuated jarring apparatus;

Fig. 181s a vertical sectional View taken throu h on ofthe' cylinders of the fluid-actuated apparatus, disclosing its internal'structuref Fig. 19 is a horizontal sectional view on =th plane indicated by the line-XIX--XIX of Fig. 18;

view of one of Fig. 20 is a similar view on the line XX-XX of Fig. 18.

Referring more particularly to the drawings,

and the form of the invention illustrated in the latter element the cable extends over the usual crown block or sheave, not shown, at the top of thederrick 4. From the crown block, the cable descends vertically and axially of the derrick, similarly passing through the tubing or casing having suspended from the lower end -thereof'the usual percussive type drilling tools,

not-shown, employed in the drilling of well openings. As previously stated, it is not uncommon in thedrilling of wells for the drill tools to become accidentally'lodged against movement in the bottom of the well opening, and the present invention provides an improved jar, indicated generally at l, disposed at the ground line 3, and adapted for facilitating the release of such jammed or caught tools. 7

In a simple embodiment of the invention, the jar is placed on acribbing 8, composed of crossed timbers, located around the upper end of the tubing or casing 3, as shown in Figs. 1 and 2. Placed on thiscribbing is the substantially sectionalized base9 of the jar, said base being employed to transmit the impact of the jar through the timber cribbing to the ground. The base is composed of separablesections so that it can be conveniently placed around the drilling cable, tubing or casingi :As shown particularly in Figs. Zand- B, thebase, in this instance, is composed of a pair of'duplicative sections lit-4!}, each of which includes a horizontally arranged bottom flange ll, adapted to rest on the cribbing 3 and an upstanding semicircular collar I2, the latter having formed therein a horizontal anvil seat I3.

The, collar l2'is united with the flange II and each section is, reenforced by means of radially dispos'edribs M, the sections l0i0 being bolted together-as at l5.

' Adapted to be seated on the base 9 is an impact-receiving anvil It. This anvil loosely receives for free movement in the center thereof the drill cable 6. Preferably, the anvil comprises a' pair of-separable sections I! and I8 which may be assembled by being placed around the line 6. These sections have vertical meeting faces l9 which areoffset laterally with respect to the drill line,- the said faces terminating in horizontally disposed matching surfaces 26. The vertical face IQ of each of the sections I! and I8 is provided with a' slot 2| for the'reception of the cable 6. Further, the sections of the anvil are secured together by means of angularly arranged bolts 22, placedon each side of the cable. As in the case of the base 9, the sectionalized construction of the anvil enables the same to be readily positioned about the cable.

The hammer 23 of the jar comprises a pair of sections 2 324 having adjoining vertical faces 25 in whichshallow registering grooves are provided for the reception of the cable 6. Angularly extending clamping boltsZE pass through the sections 24-44 in order to bring the faces 25, or the groovesthereof, into clamping engagement with madam anviI'J-I 6.: The two-part;- construction of thehanr, merenables -;the-, same Qo-be "readily clamped :to' the drill cable' whenwthe latter ,iS 3 in its operative, position; The-faces-25. of thesectionsr24 ter-mi nate in oppositelyiextending and vertically; spaced-,- horizontal shoulders 21, which are held inposi-',. tive engagement by the angularity of the clampl ing bolts 26. The-hammer may be provided at its upper end with ball sections-28,.the; latter, being 'spacedto provide ran; opening 29 through which the cable '6 passes;

In-the operation of the jar, following the lodg ing orjamming. of the-drill tools in the bottom of the well opening;- the (cable Eris drawn ,tautl, and placed under'initial tension-(by rotating the. bull wheel the cable having first =-been discone nectedqfrom the working. head of the pivoted walking beam, shown at '30.. With the cable under thisinitial tension, the base}! is positioned} on the cribbing 8 around the cable, this being; followed by the positioning ,of -:the anvil on. said base anclnaround. the cable, after, the manner depictedyin Figs. -1 and 2n, Therhammer 23 is then clamped 'tothe ,cable withthe lower ,surface of the hammer, in seating contactwith theuppera surface of the anvil. When thisarrangement of the jar membersihasibeen.effected, thecable is againpstretched -tocause, the elevation of .the, hammer and tits, separation from the .anvil, and upon the completionof thissecond cable stretch,- ingoperation, the (forces-"so stretching the. cable are suddenly released, causing, the. hammer to be r brought into" sharp timpacteimparting ,engagement with thetanvil.

Suchan operatiompr tsequencenoi, operations, results-in generating-a sharp longitudinal-aways motion in, the! taut drilling line, which travels, down to the, lodgedtools in, the bottom of the well,- subjecting such ,tools, to asharp ,jar which, inmost: cases, 1 will: effect their release. If the, tools; are moved without being completely, freed, to an extent-releasing the tension on the cable; line, it will be necessary tounclamp the hammer, restore the desired-initial tension oILthe cable line,; then again fasten the hammer to the l cable with the hammerresting; on the anvil .andrepeat the operations. This will be contl'nueduntil the. drilling tools come freecor, under severe conditions, the-line breaks; From the nature of the operation, the breaking; or parting of t the cable customarily takes placeclose to the swivel. socket to whichthe lower endiofcthe cable is connected With the string-of drilling tools Such a point of. parting-is desirable, in that it enablestheentireline to be-removed, withoutportions thereof .coiling in the bottom of, the well opening, and there,- by facilitates the operation of .extricating the lodged drill by means. of theusual fishing tools. Various r appliances may be employed. for rimparting the secondary stretching or tensioning forcesto the-cableB in order to elevate the ham? mer fromgthe anvil of the jar. The means for; accomplishing this} operation, illustrated in Figs. Lto 8, comprise a tug rope or line 3l, oneend of the latter being connected with a spudding shoe 32- detachably receivedwon the dead end ofthe cableline 6 contiguous to the drum or bull wheel 5. The other end of the tug rope. or line is connected}with,anadjustable wrist pin 32 carried by a-crankassembly 33., As thfiwrist pin rotates, thedead end-of the;dril1ing,line. is bowed, out, which transmits lacreciprocatory, motion ,to, the, live-portion r-the drillin ab e. n t ee a: tionpoflthejan-it is necessaryto havethe ham mcr. falltunobstructedly fromthetop of its stroke mrt il' i z-im a sthe an Tbisvmdipates; hew desirabilitygof; atfree ,motion device which can be-attached toithe standard crank of the drilling machine-or rig Suchma free motion device has been'illustrated' in Figs; 7, 8 and 9. In these figures the'numerale 34 designates the crank shaft-of the; drilling rig Tocthe crank shaft,- there is keyed the usual crankarm 4 35, which forms, .a part .of ,the asseme bly 33. B'oltedras at .36.,tothe front of the. crankarm is an auxiliary crank, member .31, which rotates in unison with theshaft 34 and the arm 35., i The-member?! is; formedinregistration with the axisof the shaft 34 with a boss 38, thelatter beingiprovidedv withan axial, opening to receive thetplain shank portion of apiyoting stud 39.1 This. stud is, threadedly carried; by the axial; portion of a free ,motioncrankAll also forming, a part of the assembly 33. Around ,theoaxisof Q1 the stud 39, the, inner, face-pfthe, crank to is formed with a-circular recess whichis received the boss 38. The stud ,39 loosely, projects through the boss 38 and i the, innerend thereof is threadedjfor the receptionoi a securing nut42, which, is positioned in a. recess 43 formed in the back of the auxiliary crankmember 3].

By this construction the crank .40 may rotate freely about its pivotal axis However, one edge of the auxiliary crank, member 31 (see Fig. 9) is, provided with an integralweb 44 disposed in contact with an adjacent edge portion of the,

crank 49. when the crank assembly rotates, in a clockwise direction. During, rotation of the crank assembly throughthe lower half of its full 35 orbit of turningmoyement, the web 44 maintains contact with the crank to cause its rotation. in unison with thecrank assembly This results, in-pullingthe tug rope,3l and bowing the cable 36 to impart final tensioning forces to said cable, andthe lifting of the jar'hamrner. As the crank a'ssembly moves substantially through the upper half of its circular orbit of travel, the pull on the tug rope causes the free motion crankto turn quicklyand sharply about the axis of the stud 39, thereby releasing the tension on the cable 6 and causing the hammer of the jar to deliver a sharp-blow or impacting force to the anvil 16. Continued rotation of the crankassembly causes this operation to be successively repeated;

The wrist pin 32 is adjustable radially of the free motion crankby the provision of a journaled lead screw carried by the crank 40. This screw is received'in a threaded opening 45 formed in the slot-guided inner end of the wrist pin 32. By rotating the screw 45, the wrist pin'may be caused, to move longitudinally with respec to the axis of the screw 45, thereby varying the spacing of the wrist pin with respect to the axis of the stud 39 and consequently varying the extent of lifting motion of'the hammer. When the tug line is released by the free motion of the crank Land the hammer comes into contact with the anvil I6, the cable 6 stillis maintainedunder tensioning forces, with the result that. alOngitudinaIlymrected Wave-like motionis imparted to the taut cable below the hammer for applying to the lodged tools forces, adaptedto efiecttheirrelease. These operations ,arerepeateduntil the tools are released or, under certainsevereconditions, untilv the cable 6 parts. By reason of the forces'imr-i parted to the, cable through theoperationiof Y the jar, such parting of the cabletakes place adjacent to the point wherethelowenend of thecable is, fastened totha drilling tools;, thatis, the swiveled,

socket r connector. Itwill be'appreciated that when the line so parts, it may be withdrawn in V toto from the well-bore, thereby enablingfcon--- venient use of fishing tools inserted in the bore indicated generally by the numeral 58,.i 'posi tioned in a pit 5| formed in the ground at the top' of the Well bore 52.

fore, out of the way.

Arranged in the pit 5|, on opposite sides of the well casing or tubing 53 is a pair of anvil or impact-receiving members 54. These members are formed with axial ope'ningsior the reception of guide rods or tubes 55 which arise from spaced timbers '56 disposed in the bottom of the pit,

The guide rods or tubes 55 are of suflicientheight to extend loosely into axial openings 51. provided in a pair of slidable hammer or impact-impart-. ing members 58, the latter being guided for theirv upper portions of the. rods or' movement on the tubes 55.

To facilitate the attachment of these hammer members to the drill cable 59, use is made ofv a detachable yoke 80. This yoke is formed with a centrally disposed bar 6| which, when the jar is in use, is placed against one side of the cable 59 andis firmly clamped to the latter for movement in unison therewith bymeans of a clamping lever shown at .62] This lever'is pivoted as at 63to the side of the bar BI and its outer end is adapted to be received in a slotted bail 64; I 'his bail receives one end of the bar portion 61 of the yoke and is provided with a clamping screw 65. The inner end of this screw engage with the complemental end of the bar 6! positioned in the bail, as shown in Fig. 14, so that when the screw 65 is tightened, the bail will draw the free end of the lever inwardly and clamp the yoke in secure engagement with the cable 59.

Also, the outer ends of the yoke 5!! terminate in downwardly directed legs 68, the lower ends of which are formed on opposite sides of said legs with circular enlargements 81. To quickly connect these enlarged portions of the yoke with the hammer member 58, the said members areprovided. near their upper ends, with annulargrooves 68 in their outer sides. Adapted to occupy these grooves are arcuate ribs 59 which integrally project from the inner surfaces of separable clamping members 19, a pair of such members being connected with each of the hammer members and adapted to be permanently carried thereby. Bolts H pass through aligned openings 72 provided in each set of clamping members in order to positively'retain said members in secured connection with the impact-imparting hammers 58 by maintaining th ribs 69 seated in the grooves 88. The inner surfaces of the clamping members it are circularly recessed as at 13 for the rotatable reception of a plu 1 rality of swiveled retaining disks (4, the inn'er facesof the disks it being circularly recessed as at 15 for the reception of the enlargements 61 on the legs of the yoketll- By reference to'Fig.

By placing the jar 59' in such a pit,'the same, when not in use, will belocated'below the derrick flooring and, there;

1G it will be'noted' thatthe-inhr faces of the disks 14 are cut away to-produ'ce slots 78 which l5, as' by means of the finger extensions 71,;

which are positioned in arcuate slots 18, formed in the clamping member ID and joined with the peripheral portionsof the disks M, the latter may be rotated so thatthe slots 18 will be moved out of vertical registration with the openings 19 formed at the top of each pair of clamping memher 10, said openings being closed, as shown in Fig. 13, by the outwardly extending annular flanges 80 of the retaining disks. By this means, the yoke may be readily attached to or removed from supporting-relation with the hammer members 58.

The drill cable 59 extends upwardly from the well bore, passing around the crown block, not shown, at the top of the derrick 8| and thence downwardly of the derrick, having the dead end thereof secured to the drum of the bull wheel 82. As in the'previously described form of the invention, when the jar is'to be used, an initial tension is imparted to the drill cable by tightening the dead end of the cable around the bull wheel. When the cable has been so initially tensioned, the yoke 60 is then clamped thereto with the hammer members of the yoke in contact with the anvils 54. Following this operation, a tug line 83 is clamped to the yoke. This may be accomplished by providing the bar portion of the yoke with a second'clamping lever 84, the latter being located on the opposite side of the yoke bar 61 asregardsthe lever 62. The

lever 84 is virtually a duplicate of the "lever 62,

and has one end thereof pivoted as at 85to the yoke and its opposite or outer end received in a bail 86. A set screw 8'! is carried by this bail, and, when tightened-the inner end of the set screw 87 engages with the complemental end of the yoke bar 6| in order to bring the lever 84 into clamping engagement with the lower end of the tug line 83.

The tug line passes upwardly from the yoke through the derrick 8|, and may be trained over the crown block of the latter and thence brought downwardly for passage around a guide sheave 88, shown, in this instance, as being mounted on one of the frame legs of the derrick 8|. From the guide sheave 88, the tug line is passed to the wrist pin 32 of the free motion crank assembly 33. It will be seen that when the crank assembly rotates, the tug line will serve to elevate the yoke and hammer members of the jar, as well as portions of the drill cable 59 below the yoke and the string of tools carried by the lower end of the drill cable and positioned in the well bore. When-the tug line is so used, that part of the drill cable 59 above the yoke may be slackened, as shown'in Fig. 10, by the operation of the bull wheel 82. However, the initial tension in the length of the drill cable below the yoke is maintained, and the additional stretching of the drill cable to elevate the hammer members from the anvils 54 is performed by the operation of the tug line. When the crank 40 of the assembly 33 is released for rapid turning movement under the pull "of the tug line and the appliances sus pended therefrom, the hammer members descend upon the anvils 54, abruptly checking the con traction of thedrill cable'59, and imparting forces racemes? -to the 'drillfcable'zsadapted for? the release ofkthe fledged tools i'carried thereby.

A further variation of; the invention has "been illustrated in Fi'gsl 171 .r'toe20 inclusive, *wherein 11 the jar apparatus has' been disclosed as being of r the zfluidsactuated. type; rather :than :the strictly mechanical types? previously set' forth,

shown in these. figures, the; fluid-actuated jarrcomprises a pairzof cylindersiindicated at 90, --1the lsame being; mounted; on the. ground; or; derrick'fifioor,inaequallyspaced relation on opposite sides of the 'weltabore 9 I Each of I the cylinders comprises a base'casting 92; havingan upstand- 1 ing annular fiangexfllaroundwhich. is positioned and isuitably secured the lower; end-10f a cylindri- -:caltcasing 94. "eEachbase; casting is further formediwith anannular passage95 and'arranged --above1 this passage; and seated; on; the beveled -walls :96. thereofzis: aircylinden member F91. The lower portion of the cylinder member hasrelatively thickened walls 98,:1whichzterminate in an 5 annular" shoulder 99; above .which shoulder. the internal diameterof theicylinder. member is greaterthan its diameter below the shoulder.

. Positioned for sliding movement in each: of the cylinder members? 91 is: aspiston I00. Intermediately of itsflength, theipiston is formed with a head I I which is slidably received in the cham- .ber I02, formed by enlarging the .internal diameter of the cylindenutotthe extent indicated --by the shoulder .99. .Thehead I.0I .maybeiprovided'with the usual piston rings I03. 7 Below the 1 head :I 0 I, each piston *is reduced. in diameter .to correspond .with thepinternal diameter. of the lower portionsof thescylinder -9.I,:.as.produced by.

.the thickened walls 190. The upper ends of the pistons I00 slidably projectthrough the tops of the cylinders 90 and are connected with aclamping yoke I04. In Fig, 1'7, the'y0ke I04 has been shown as secured towthe :upper end I05 ofsa string of well tubing, theelatter. extending, as usual, intozthe wellwbore and axially ofthe well -casing, indicated" at r105. iTWhen-so connected with the tubing I05; the apparatus may be used incliberating a' -lodged packer within thewell bore. How.ever, if desired, the yoke IM may be joined with a drill :cable,c as .in. theuprevious'ly described forms of .:the invention.

To, efiect the elevation of the vpistons I00 in the. cylindermembers .91'. inorder to apply tensioning forces toithevtubing I05, or any associated jdrillcable; I mayemploy a motor driven ptractorvehicleof theltype indicated at I01, utilizing the engine of thisvehi'cle forloperating a fluid pump or compressor I08; From. the'fluid' inlet and outletqofthe pumpor compressor. I08, there may be convenientlyqextended pipe or hose lines I09, H0, the former ofwwhich-being employed to conduct a fiuidunder positive flow to the fluid inlets III of the cylinders -90 andthelatter .to return-suchfiuid to thepump orcompressor. As a practical matter, I havefound it convenientto use oil as the motivating'fluid.

I To control the introduction of the motivating fluid into-said cylinders and itsrdischarge there- 'from, the base 92of .eachcylinder is provided with a valve chamber II 2. S1idably positioned in each of these chambersis abalanced typefsp'ool "valve II3. With 'thevalve of each cylinder positioned as'shown inFig; 20, oilor other-fluid en- "tering the bottom of the cylinder through the pipeline I09 and the inlet I I I', flows" around the "reduced central portion I I4- of the valve and pa'ssesbyway of a port -I I5 into the circular 1. orwmorer' vertical: passages "II 6, 5 provided; in g the thickened walls 98 v of eachofwthe cylinder-memhere 91. Fluid pressures of the" order of-several hundreds, of. pounds; :per square inch; may thus 5 T be "applied to? the under 1 surfaces ,of: the piston heads' lflI, causing theelevation of said pistons.

the? yoke :I 04 carried fthereby, and thestretching or tensioning .of thewell ftubing -ordrill cables :"connected therewith.

10 -Following: predetermined'elevation oigtherpistons iandithe consequent tens'iomng :ofythe; associ'ated: well bore 1 devices, the operating position of the spool valve Ii! 3 in each cylinder is reversed to spermit: of the rapid: descent of :the. pistons :a'ndfto gsharp'lyc arrest "suchq: descent .Whi'le' the: devices gripped: by the; yoke? .104: are :yet: under. tension. Conveniently; this result may be accomplished by the provision bra bypass port I llfiwhichtiextends from the fluid inlet I I Iztoone endzofejthei valve chamber II2. Normallyaclosing the portziI't-isian adjustable. spring-loaded valve :IFI 8 which may be s'et to open theport :Ir'I I when the fluid." pressures "within theinlet I II (reach azpredetermihedfllolume. Whentheport III is open, fluidt'pressures aredeveloped on one' end of the valve I I3,:causing the latterzto' shift' its position in :the chamber .I I 2, 'thereby closingthe inlet :'I I I and .uncovering the outlet opening II 9." which communicates-with the I fluid return line-'L'I 0. s Bec-ause ofy'the' weights im- 0 p'ose'd ithereonaby the. .well' boreappliances sus- J pended-from -the yokeI I04; thepistons move,,rapidly downwardly in the cylinder members 91 ,':fluid being displaced iromlbeneath the heads :I 0 I' and being discharged through'ithe .verticalipassages Il6, the annular passage 95, port 'I I5; .valve chamber H2 and thence throughioutletopening II9 to the return 1ine I I0.

Inoperation, the:chamber or reservoir I20, which is formed in each:of the cylinders 90 between the casing 94:. thereofiand the cylinder .member 91, is filled with the motivating fluid. The base 92 of eachcylinder is. provided'withrestricted fluid conducting passages I2I which lead from thebottom of the reservoir I20, asshown in Fig. 18, to a valvepocket 122,.disposed below and in registration with vthezpiston I00. A disk valve assembly I231is employed.- to-permit. ofyfluid --.'flow..from theiIBSEIVOlI I20 -,through ,the passages I21 and intothe bottom of. thecylinder member 50. 91 when the associated piston I 00 moves upwardly, breaking any; vacuum whichmay exist in the bottom of the cylinder-structure-;-andfacilitating I the upward movementiofgthe piston. Upon the descent of the piston, however,-the disk valve assembly, closes, ;=so' -th'at the oil or'other fluid in the-bottom of the cylinder structure mayescape into the reservoir; onlyby Way of the circularly T arrangedrows. of restrictedapertures shownat These apertures are formed in the bottom portions of the cylinder members! and any desired number of these verticallyarranged rows otaperturesmaymeused. gAs the piston descends, these rows: ofapertures are-successively covered by the piston to provide forthe'clesired impact action of i the" pistons on-thejoperating fluidpandg stationary A parts'of the apparatus. A row aofjsp'a'cedzports I25 may be provided in the upper portions of the cylindermembers 9'I-abovethe erllargedhead WI .7 of e'ach of the pistons [00,:toprovidefor the flow of the *operating'fluid between .the reservoir I20 andthe interior of the cylinder members 91 above "-the h'eadsIOI.

T0 automatically reverse theixpositions of the "*pas'sage 95;thencepassing-upwardly throughone -"valves= II3 iohowingthe desired descent of the pistons lot 'aiid ag aih"tojintroduce fluid under "pressure into the cylinder structures to elevate the pistons, each-of the base casting 92 is provided wit-h a second-spring-loaded valve .126 of the same type as indicated at H8. Each of the valves I26 'is' employed to govern the flow-'of the operating fluid fromthe bottom of the cylinder member 91 through a passage I 21 formed in the casting 92 and leading to the valve chamber I I2. Each valve I26 is operative so that whenpredetermined fluid pressures are applied thereto, the valvewill open, 'allowing'the fluid to enter one end of the chamber H2 and exert force on the spool valve I I3 to shift the latter'b'ack to the Position disclosed in Fig. 20. By these means, the pistons I are automatically pulsated to produce the desired jarring action on .the well bore appliances connected therewith.

The stud bolts,'shown at I28 in Fig. 19, are employed in uniting the cylinder members 91 with their associated base castings 92;

. The present invention thus provides a jar apparatus which is adapted to be operated fromthe ground surface at the top of the well bore in which the lodged appliances are located. The apparatus may be quickly applied to an associated drill cable or other elongated wellappliance and actuated with the use of the customary equipment of'a well rig. The use of the apparatus results in marked savings both in time and cost with respect to previously used methods and appliances, and has, further, the advantage of convenience in application and control because of its accessible location above the well opening.

' means prior to complete contraction of the cable when the latter is released from the stretching forces applied thereto.

2; Apparatus forreleasing devices lodged in a well bore, comprising a hammer movable in. unison with said devices at the top of the well bore, means for stretching the devices and suddenly releasing the same for contraction, and a groundsupported anvil engageable with said hammer when said devices have been partially contracted following release of the stretching forces.

3. In apparatus for efiecting the release of lodged well-drilling tools suspended from an operating cable and disposed in a well bore, impact-imparting means fixed to said cable at the top of the well bore, means for applying tensioning forces to said cable to elongate'the same, cooperative means for effecting a quick release of said tensioning forces applied to the cable'and cause the sudden contraction of the cable, and a ground-carried impact-receiving instrumentality for arresting the movement of said impact-imparting means prior to complete contraction of said cable'in reacting to therelease of said tensioning forces.

4. The method of releasing a cable-actuated drilling tool lodged against normal movement in, a well bore, comprising applying to the actuating cable of such a drill tensioning forces to cause an elongation of the cable, suddenly releasingssaid'tensioning forcesto effect a sharp reacting contraction of the cable. and mechanv 6. The method of releasing a trapped cableof such drill. toolsfrom the top of the well bore -initial tensioning forces, securing tothe initially tensioning cable for movement in unison therewith an impact-imparting instrumentality, .applying further tensioning forces to the cable to additionally stretch and elongate the same, suddenly releasing the .cable fromsaid tensioning forces to effect its sharp contraction, and interrupting the contraction of the cable prior to complete expenditure of, the contracting energy thereof: by causing .said impact-imparting member to engage with a ground-carried impact-receiving member.

: actuated well-drilling tool positioned in a well bore, comprising tensioning the cable to elongate the same, suddenly releasing the tension-producing forces to effect sharp contraction of the cable, and abruptly arresting the contraction of the cable prior tofinal expenditure of its contracting energy to impart releasing forces to the trapped drilling tool carried by the lower end of ciated derrick/mounted drill cable, means for.

stretching the drillcable to space said hammer member from saidanvil, and means for effecting a sudden release of the cable stretching means tobring said hammer member, upon the contraction of the cable, into forcible impact-imparting engagement with the anvil.

8. Apparatus for releasing devices lodged against normal movement in well bores, comprising impact-delivering mechanism located above a well bore, means for securing said mechanism to an elongated tensionable member disposed in the wellbore sothat said means moves in unison with said member, means for placing said member under tension to elastically elongate the same, an impact-receiving element mounted adjacent a to the upper end of-the well bore, and means for quickly releasing said member following elongation thereof to cause its partial contraction,

' whereby to bring said mechanism into impact delivering coaction with said element prior to complete expenditure of the 'tensioning energy previously applied thereto.

9. The method of releasing devices lodged against normal movement in subterranean well bores comprising: subjecting an elongated tensionable member disposed in a well bore to forces producing elongation thereof, quickly releasing said member from said tensioning forces to cause its sharp contraction, and abruptly arresting the contraction of said member priorto full expenditure of its "contracting energy to impart thereto longitudinally directed dislodging forces which travel the length of saidmember and said bore to the aifectedlregions in the well bo're.

10. The method ,of releasing devices lodged producing elongatlon thereof, quickly releasing said member from said tensioning forces to cause its sharp contraction, and abruptly arresting the contraction of said member prior to full expenditure of its contracting energy to impart thereto longitudinally directed dislodging forces which travel the length of said member and said bore to the affected regions in the well bore, said tensioning forces being applied to said member from the top of the well bore.

11. Apparatus for releasing devices lodged against normal movement in a well bore, comprising a pair of impact-imparting devices, means for detachably securing said devices to an elongated tensionable member disposed in the well bore for movement in unison therewith, said devices being disposed when fixed to said member above the well bore, means for stretching said member by applying tensioning forces thereto and following predetermined stretching suddenly releasing the same for contraction, and ground-supported impact-receiving elements engageable with said devices when said member has been partially contracted following release of the stretching forces.

12. Apparatus for releasing devices lodged against normal Withdrawal movement in well bores, comprising impact-delivering mechanism located above a well bore, means for securing said mechanism to an elongated tensionable member disposed in the well bore, whereby to cause said delivering mechanism to move in unison with said member, fluid actuated means cooperative with said delivering mechanism for placing said member under tension to elastically elongate the same, and valve means for governing the operation of said fluid actuated means to suddenly release the tension on said elongated member to cause rapid contraction thereof.

13. Apparatus for releasing devices lodged in a well bore comprising a cylinder disposed above the well bore, a piston slidably mounted in said cylinder and projecting beyond one end thereof, means for detachably clamping the projecting end of said piston to an elongated tensionable member disposed in the well bore, means for admitting a fluid under pressure into said cylinder for effecting movement of said piston and thereby apply tensioning forces to said elongated member, means for effecting a rapid discharge of fluid from said cylinder to provide for sharp contraction of said elongated member following predetermined tensioning thereof, and means for abruptly terminating the discharge of fluid from said cylinder prior to full contraction of the elongated member in response to the release of said tensioning forces to sharply arrest the movement of said piston and thereby apply dislodging forces to said elongated member.

14. A surface jar for releasing trapped well bore appliances comprising a cylinder, a piston slidably mounted in said cylinder and projecting through one end thereof, clamping means carried by the projecting end of said piston for connecting the latter with an elongated tensionable appliance extending longitudinally into the well bore, means for supplying a fluid under pressure to said cylinder to produce movement of said piston effecting the tensioning and elongation of said appliance, said means including a pressure balanced control valve, and means governed by the fluid pressures established within said cylinder for alternately moving said valve between fluid admitting and discharge positions.

15. Shock-producing apparatus for releasing trapped wel1 bore appliances, comprising a percussion member adapted for detachable securement to an elongated tensionable member extending into the well bore, a rotatable power driven crank, a free-motion element positively rotatable with said crank during one part of its orbit of movement and independently rotatable with respect to said crank through the remaining portion of its orbit of rotation, and flexible means cooperative with said free-motion element and said elongated member to place the latter under tension and actuate said percussion member.

16. Shock-producing apparatus for use in releasing trapped well bore appliances, comprising a movable percussion device, means for detachably clamping said device to the actuating cable of a well drilling tool at the top of a wel1 bore in which the cable is situated, a ground-supported impact-receiving appliance cooperative with said percussion device, means for placing said cable under initial tension, means for applying additional tension to said cable to elongate the same and space said percussion device from the impact-receiving appliance, and means for suddenly releasing the cable from such additionally applied tensioning forces to cause said percussion device upon the contraction of the cable to forcibly engage the impact-receiving appliance, said latter means embodying a rotatable power driven crank, an element positively rotatable with said crank through one portion of its full orbit of rotation and independently rotatable with respect to said crank through the remaining portion of its orbit of rotation, and a flexible connection between said element and said cable.

17. Jar apparatus for effecting the release of lodged well drilling tools suspended from an operating cable and disposed in a well bore, impact-imparting means detachably secured to said cable at the top of the well bore, means for applying tensioning forces to said cable to elongate the same, cooperative means for effecting a quick release of said tensioning forces applied to said cable to cause its sudden contraction, an impact-receiving instrumentality for arresting the movement of said impact-imparting means prior to complete contraction of said cable in reacting to the release of said tensioning forces, and a shock-absorbing base for effecting the support of said impact-receiving instrumentality.

18. A surface jar for effecting the release of lodged wel1-drilling tools suspended from the operating cable and disposed in a well bore, a pair of impact-producing members, a yoke uniting said members, clamping devices carried by said yoke for detachably securing the latter to said cable for movement in unison therewith, impact-receiving appliances aligned with said impact-producing members, means for applying tensioning forces to said cable to elongate the same, and cooperative means for effecting a quick release of said tensioning forces to cause the sudden contraction of said cable and the rotatable engagement of the impact-producing members with said impact-receiving appliances.

JOHN F. KENDRICK. 

